This invention relates to a field effect transistor, and more particular to a field effect transistor using so-called quantum boxes (also called quantum dots) and having a differential negative resistance.
Great hopes are placed to transistors having a differential negative resistance as high-functional devices. For one reason, it is known that, by utilizing a strong non-linearity appearing in their current-to-voltage characteristics (I-V characteristics), a logic circuit may be composed of a less number of transistors. This advantage is of a great importance, considering the present situation where a delay in wiring restricts performance of logic ICs.
There are some transistors reported, having a differential negative resistance. The most widely known one of them is of a type called resonant tunneling hot electron transistors (RHET).
However, such RHET transistors, because of utilizing a resonant tunnel phenomenon, need a semiconductor heterojunction of good uniformity, which compels their structure to be longitudinal with respect to the substrate. Longitudinal RHETs are inconvenient for incorporation into ICs. There is thus a demand for transistors having a differential negative resistance and having a planar structure for easier integration.